Effect of Side Groups on the Surface Parameters and Antifouling Properties of Poly(<i>N</i>‐Alkyl Acrylamide)‐Coated Surfaces

Abstract Understanding the origins of antifouling properties in polymer materials is essential for improving their biocompatibility. In this work, the effect of side groups in poly( N ‐alkyl acrylamide)s on their resistance to non‐specific interactions with blood proteins is studied. Using reversible addition‐fragmentation chain transfer (RAFT) polymerization protocol, a library of acrylamide‐based polymers is synthesized, including poly(( N ‐propyl)acrylamide) (pPAM), poly(( N ‐ethyl)acrylamide) (pEAM), poly( N ‐(2‐fluoroethyl)acrylamide) (pFEAM) and poly( N ‐(2‐hydroxyethyl)acrylamide) (pHEAM), with four distinct chain lengths, i.e. degrees of polymerization ( DP = 25, 50, 75, and 100). The polymer chains are attached to gold substrates under the most widely used “grafting to” approach through the trithiocarbonate chain end groups. The physical properties of the resulting polymer coatings are studied and evaluated their antifouling properties against blood plasma. While the of pPAM and pEAM reduced the fouling to a certain extent, semi‐fluorinated pFEAM and pHEAM coatings showed improved fouling resistance with increasing DP and enhanced brush‐like character. Notably, pFEAM and pHEAM coatings of nominal DP = 100 manage to reduce the fouling by more than 90% when compared to bare gold surfaces. These findings highlight the critical role of polymer side groups and chain length in designing antifouling coatings.